Besides applications, wherein classical active carbons are used as a mass product, applications requiring special high-performance active carbons are becoming increasingly important. These are applications, wherein the required amounts of active carbon for a certain purpose and a certain time of use have to be kept low, and nevertheless excellent adsorption properties (adsorption kinetics, capacity) are required. These are in particular mobile applications, such as for filters in vehicles (cars, aircrafts, etc.) or in gas masks, but also in building air filters. Besides a favorable capacity/weight ratio, other requirements play a role, such as a low pressure loss over a filter containing the active carbon. This also means, however, that it is not always possible as an additional requirement to use active carbons maximized with regard to the BET surface; rather, it may be necessary to use active carbons, which have nevertheless outstanding adsorption properties, in spite of a moderate BET surface. In any case, excellent adsorption properties are required, in particular in the case of filters, which are intended to protect persons from toxic gases.
From the document EP 0 326 271, an active carbon is known in the art, which can be prepared from a polysulfonated copolymer. It has a multimodal pore size distribution, i.e. a high share of mesopores and macropores.
From the document WO 96/21616, an active carbon prepared from monosulfonated copolymers is known in the art. This active carbon, too, has a relatively high share of mesopores and macropores.
From the document WO 99/28234, a method for preparing an active carbon from styrene-divinylbenzene copolymers is known in the art, and by variation of parameters of the method, the pore size distribution can be adjusted for a wide range. The active carbons specifically prepared according to this document have, however, a share of pores>3 nm of more than 13 % v/v of the total open porosity.
All above prior art active carbons have the common drawback that the adsorption capacity is not yet sufficient for all requirements, which are imposed on high-performance adsorbents, in particular in the mobile field.